Photographic apparatus

ABSTRACT

A photographic apparatus comprises a movable platform and a controller. The movable platform has an imager and is movable and rotatable in an xy plane. The controller performs a movement control of the movable platform for one of a translational movement and a rotational movement. The translational movement includes at least one of a first stabilization for correcting hand shake caused by yaw around the y direction and a second stabilization for correcting hand shake caused by pitch around the x direction. The rotational movement rotates the movable platform in the xy plane. The controller determines which of the translational movement and the rotational movement is to be performed, on the basis of a first hand-shake parameter caused by yaw that is calculated for the first stabilization and a second hand-shake parameter caused by pitch that is calculated for the second stabilization.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a photographic apparatus, and inparticular, to a photographic apparatus that performs a rotationalmovement such as an inclination correction or the like.

2. Description of the Related Art

There is known a type of image stabilization (also known as anti-shake,but hereinafter, simply “stabilization”) apparatus for a photographicapparatus. The image stabilization apparatus corrects for the effects ofhand shake by moving a movable platform including an image stabilizationlens or by moving an imager (an imaging sensor) in an xy planeperpendicular to an optical axis of a taking lens of the photographicapparatus, in accordance with the amount of hand shake that occursduring the imaging process.

Japanese unexamined patent publication (KOKAI) No. 2006-71743 disclosesan image stabilization apparatus that calculates hand-shake quantity onthe basis of hand shake due to yaw, pitch, and roll, and then performs astabilization on the basis of the hand-shake quantity (the first,second, and third hand-shake angles).

In this stabilization operation, the following stabilization functionsare performed: a translational movement including a first stabilizationthat corrects the hand shake caused by yaw and a second stabilizationthat corrects the hand shake caused by pitch, and a rotational movementincluding a third stabilization that corrects the hand shake caused byroll.

In the translational movement, the movable platform is moved in the xyplane without rotational movement.

In the rotational movement, the movable platform is rotated in the xyplane.

However, in general, the movement range of the movable platformincluding the imager forms a rectangle. Therefore, the rotationalmovement of the movable platform for the third stabilization limits themovable ranges of the movable platform in the x and y directionsavailable to translational movement (the first and secondstabilizations).

When the movable ranges of the movable platform available for thetranslational movement are limited, the translational movement cannot beperformed accurately.

Conversely, the translational movement limits the movable ranges of themovable platform for rotational movement, thus preventing it from beingperformed accurately.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide aphotographic apparatus that performs the rotational movementeffectively.

According to the present invention, a photographic apparatus comprises amovable platform and a controller.

The movable platform has an imager that captures an optical imagethrough a taking lens, and is movable and rotatable in an xy planeperpendicular to an optical axis of the taking lens.

The controller performs a movement control of the movable platform forone of a translational movement and a rotational movement. Thetranslational movement includes at least one of a first stabilizationfor correcting hand shake caused by yaw around the y direction and asecond stabilization for correcting hand shake caused by pitch aroundthe x direction. The x direction is perpendicular to the optical axis.The y direction is perpendicular to the x direction and the opticalaxis. The rotational movement rotates the movable platform in the xyplane.

The controller determines which of the translational movement and therotational movement is to be performed, on the basis of a firsthand-shake parameter caused by yaw that is calculated for the firststabilization and a second hand-shake parameter caused by pitch that iscalculated for the second stabilization.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and advantages of the present invention will be betterunderstood from the following description, with reference to theaccompanying drawings in which:

FIG. 1 is a perspective view of the embodiment of the photographicapparatus as viewed from the rear;

FIG. 2 is a front view of the photographic apparatus, when thephotographic apparatus is held in the first horizontal orientation;

FIG. 3 is a circuit construction diagram of the photographic apparatus;

FIG. 4 is a flowchart that shows the main operation of the photographicapparatus;

FIG. 5 is a flowchart that shows the details of the timer interruptprocess;

FIG. 6 illustrates the calculations involved in the stabilization andinclination correction;

FIG. 7 is a construction diagram of the movable platform;

FIG. 8 is a flowchart showing the details of the calculation of thethird digital displacement angle;

FIG. 9 is a front view of the photographic apparatus, when thephotographic apparatus is held in the second horizontal orientation;

FIG. 10 is a front view of the photographic apparatus, when thephotographic apparatus is held in the first vertical orientation;

FIG. 11 is a front view of the photographic apparatus, when thephotographic apparatus is held in the second vertical orientation;

FIG. 12 is a front view of the photographic apparatus, and Kθ_(n) is theangle formed when the photographic apparatus is rotated (inclined) in acounter-clockwise direction as viewed from the front, away from thefirst horizontal orientation;

FIG. 13 is a front view of the photographic apparatus, and Kθ_(n) is theangle formed when the photographic apparatus is rotated (inclined) in acounter-clockwise direction as viewed from the front, away from thefirst vertical orientation;

FIG. 14 is a front view of the photographic apparatus, and Kθ_(n) is theangle formed when the photographic apparatus is rotated (inclined) in acounter-clockwise direction as viewed from the front, away from thesecond horizontal orientation; and

FIG. 15 is a front view of the photographic apparatus, and Kθ_(n) is theangle formed when the photographic apparatus is rotated (inclined) in acounter-clockwise direction as viewed from the front, away from thesecond vertical orientation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is described below with reference to theembodiment shown in the drawings. In the embodiment, the photographicapparatus 1 is a digital camera. A camera lens (i.e. taking lens) 67 ofthe photographic apparatus 1 has the optical axis LX.

By way of orientation in the embodiment, the x direction, the ydirection, and the z direction are defined (see FIG. 1). The x directionis the direction perpendicular to the optical axis LX. The y directionis the direction perpendicular to the optical axis LX and the xdirection. The z direction is the direction parallel to the optical axisLX and perpendicular to both the x direction and the y direction.

The relationships between the direction of gravitational force and the xdirection, the y direction, and the z direction, change according to theorientation of the photographic apparatus 1.

For example, when the photographic apparatus 1 is held in the firsthorizontal orientation, in other words, when the photographic apparatus1 is held horizontally and the upper surface of the photographicapparatus 1 faces upward (see FIG. 2), the x direction and the zdirection are perpendicular to the direction of gravitational force andthe y direction is parallel to the direction of gravitational force.

When the photographic apparatus 1 is held in the second horizontalorientation, in other words, when the photographic apparatus 1 is heldhorizontally and the lower surface of the photographic apparatus 1 facesupward (see FIG. 9), the x direction and the z direction areperpendicular to the direction of gravitational force and the ydirection is parallel to the direction of gravitational force.

When the photographic apparatus 1 is held in the first verticalorientation, in other words, when the photographic apparatus 1 is heldvertically and one of the side surfaces of the photographic apparatus 1faces upward (see FIG. 10), the x direction is parallel to the directionof gravitational force and the y direction and the z direction areperpendicular to the direction of gravitational force.

When the photographic apparatus 1 is held in the second verticalorientation, in other words, when the photographic apparatus 1 is heldvertically and the other side surface of the photographic apparatus 1faces upward (see FIG. 11), the x direction is parallel to the directionof gravitational force and the y direction and the z direction areperpendicular to the direction of gravitational force.

When the front surface of the photographic apparatus 1 faces in thedirection of gravitational force, the x direction and the y directionare perpendicular to the direction of gravitational force and the zdirection is parallel to the direction of gravitational force. The frontsurface of the photographic apparatus 1 is the side on which camera lens67 is attached.

The imaging part of the photographic apparatus 1 comprises a PON button11, a PON switch 11 a, a photometric switch 12 a, a shutter releasebutton 13, a shutter release switch 13 a for an exposure operation, acorrection button 14, a correction switch 14 a, a display 17 such as anLCD monitor or the like, a mirror-aperture-shutter unit 18, a DSP 19, aCPU 21, an AE (automatic exposure) unit 23, an AF (automatic focus) unit24, an imaging unit 39 a in the correction unit 30, and the camera lens67 (see FIGS. 1, 2, and 3).

Whether the PON switch 11 a is in the ON state or OFF state isdetermined by the state of the PON button 11. The ON/OFF states of thephotographic apparatus 1 correspond to the ON/OFF states of the PONswitch 11 a.

The subject image is captured as an optical image through the cameralens 67 by the imaging unit 39 a, and the captured image is displayed onthe display 17. The subject image can be optically observed through theoptical finder (not depicted).

When the shutter release button 13 is partially depressed by theoperator, the photometric switch 12 a changes to the ON state so thatthe photometric operation, the AF sensing operation, and the focusingoperation are performed.

When the shutter release button 13 is fully depressed by the operator,the shutter release switch 13 a changes to the ON state so that theimaging operation by the imaging unit 39 a (the imaging apparatus) isperformed, and the captured image is stored.

The CPU 21 performs a release-sequence operation including the imagingoperation after the shutter release switch 13 a is set to the ON state.

The mirror-aperture-shutter unit 18 is connected to port P7 of the CPU21 and performs an UP/DOWN operation of the mirror (a mirror-upoperation and a mirror-down operation), an OPEN/CLOSE operation of theaperture, and an OPEN/CLOSE operation of the shutter corresponding tothe ON state of the shutter release switch 13 a.

The camera lens 67 is an interchangeable lens of the photographicapparatus 1 and is connected to port P8 of the CPU 21. The camera lens67 outputs the lens information including the lens coefficient F etc.,stored in a built-in ROM in the camera lens 67, to the CPU 21, when thephotometric operation is performed.

The DSP 19 is connected to port P9 of the CPU 21 and to the imaging unit39 a. Based on a command from the CPU 21, the DSP 19 performs thecalculation operations, such as the image-processing operation, etc., onthe image signal obtained by the imaging operation of the imaging unit39 a.

The CPU 21 is a control apparatus that controls each part of thephotographic apparatus 1 in its imaging operation, and in itsstabilization (i.e. anti-shake) and inclination correction.

The stabilization and inclination correction includes both the movementcontrol of the movable platform 30 a and position-detection efforts.

In the embodiment, the stabilization includes a first stabilization thatmoves the movable platform 30 a in the x direction and a secondstabilization that moves the movable platform 30 a in the y direction.

Furthermore, the CPU 21 stores the value of the correction parameter SRthat indicates whether the photographic apparatus 1 is in the correctionmode or not, the value of the release-state parameter RP, the value ofthe mirror state parameter MP, and the value of the holding stateparameter HND.

The value of the release-state parameter RP changes with respect to therelease-sequence operation. When the release-sequence operation isperformed, the value of the release-state parameter RP is set to 1 (seesteps S21 to S28 in FIG. 4), otherwise, the value of the release-stateparameter RP is set (reset) to 0 (see steps S12 and S28 in FIG. 4).

While the mirror-up operation is performed before the exposure operationfor the imaging operation, the value of the mirror state parameter MP isset to 1 (see step S22 in FIG. 4); otherwise, the value of the mirrorstate parameter MP is set to 0 (see step S24 in FIG. 4).

Whether the mirror-up operation of the photographic apparatus 1 isfinished is determined by the detection of the ON/OFF states of amechanical switch (not depicted). Whether the mirror-down operation ofthe photographic apparatus 1 is finished is determined by the detectionof the completion of the shutter charge.

The holding state parameter HND is the parameter whose value changes inaccordance with the holding state of the photographic apparatus 1.

Specifically, when at least one of either a first condition that theabsolute value of the first digital angular velocity VVx_(n), which isthe first hand-shake parameter, is greater than the first threshold Rex,or a second condition that the absolute value of the second digitalangular velocity VVy_(n), which is the second hand-shake parameter, isgreater than the second threshold Rey, is fulfilled, it is determinedthat the photographic apparatus 1 is held by the operator's hand so thatthe hand shake of the photographic apparatus 1 tends to occur and thevalue of the holding state parameter HND is set to 1 (|VVx_(n)|>Rex or|VVy_(n)|>Rey, HND=1). Namely, the holding state parameter HND is set to1, when at least one of the first and second hand-shake parameters isgreater than the threshold.

In this case, the stabilization (the first and second stabilizations) isperformed, but the inclination correction is not performed.

When the first and second conditions are not fulfilled, it is determinedthat the photographic apparatus 1 is fixed on a tripod etc., so that thehand shake of the photographic apparatus 1 does not tend to occur andthe value of the holding state parameter HND is set to 0 (|VVx_(n)|≦Rexand |VVy_(n)|≦Rey, HND=0). Namely, the holding state parameter HND isset to 0 (reset), when the first and second hand-shake parameters arenot greater than the threshold.

In this case, the stabilization (the first and second stabilizations) isnot performed, but the inclination correction is performed (see step S56in FIG. 5).

The value of the holding state parameter HND, immediately before thevalue of the release-state parameter RP is set to 1, is used fordetermining which of the stabilization (the first and secondstabilizations) or the inclination correction is to be performed.

When the first and second stabilizations are performed, the rotatablerange of the movable platform 30 a in the xy plane is narrowed comparedto when the movable platform 30 a is fixed to the center of its movementrange without moving, because the movable platform 30 a is moved in thex and y directions.

Namely, the range of the inclination angle available for the inclinationcorrection is narrowed so that it becomes difficult to perform theinclination correction accurately.

On the other hand, when the inclination correction is performed, themovable range of the movable platform 30 a in the x and y directions isnarrowed compared to when the movable platform 30 a is not rotated,because the movable platform 30 a is rotated in the xy plane.

Namely, the movable range of the movable platform 30 a available for thefirst and second stabilizations is narrowed so that it becomes difficultto perform the first and second stabilizations accurately.

In the stabilization and inclination correction of the embodiment, onthe basis of whether the hand shake of the photographic apparatus 1occurs, one of either the stabilization (the first and secondstabilizations) or the inclination correction is performed, and theother is prohibited.

Thus, one of either the stabilization (the first and secondstabilizations) or the inclination correction can be performedaccurately, corresponding to the necessity of one of them (correspondingto the priority).

Furthermore, the CPU 21 stores the values of the first digital angularvelocity signal Vx_(n), the second digital angular velocity signalVy_(n), the first digital angular velocity VVx_(n), the second digitalangular velocity VVy_(n), the first digital acceleration signal Dah_(n),the second digital acceleration signal Dav_(n), the first digitalacceleration Aah_(n), the second digital acceleration Aav_(n), the firstdigital displacement angle Kx_(n), (the hand-shake angle caused by yaw),the second digital displacement angle Ky_(n) (the hand-shake anglecaused by pitch), the third digital displacement angle Kθ_(n) (theinclination angle of the photographic apparatus 1), the horizontaldirection component of the position S_(n), Sx_(n), the verticaldirection component of the position S_(n), Sy_(n), the rotationaldirection component (the inclination angle) of the position S_(n),Sθ_(n), the first vertical direction component of the first drivingpoint, Syl_(n), the second vertical direction component of the seconddriving point, Syr_(n), the horizontal driving force Dx_(n), the firstvertical driving force Dyl_(n), the second vertical driving forceDyr_(n), the horizontal direction component of the position P_(n) afterA/D conversion, pdx_(n), the first vertical direction component of theposition P_(n) after A/D conversion, pdyl_(n), the second verticaldirection component of the position P_(n) after A/D conversion,pdyr_(n), the lens coefficient F, the first threshold Rex, the secondthreshold Rey, and the hall sensor distance coefficient HSD. The hallsensor distance coefficient HSD is the relative distance between thefirst vertical hall sensor hv1 and the second vertical hall sensor hv2in the x direction of the initial state (see FIG. 7).

In the initial state, the movable platform 30 a is positioned at thecenter of its movement range in both the x and y directions, and each ofthe four sides of the rectangle composing the outline of the imagingsurface of the imager (an imaging sensor) 39 a 1 is parallel to eitherthe x direction or the y direction.

The AE unit (exposure-calculating unit) 23 performs the photometricoperation and calculates photometric values based on the subject beingphotographed. The AE unit 23 also calculates the aperture value and theduration of the exposure operation, with respect to the photometricvalues, both of which are needed for the imaging operation. The AF unit24 performs the AF sensing operation and the corresponding focusingoperation, both of which are needed for the imaging operation. In thefocusing operation, the camera lens 67 is re-positioned along theoptical axis LX.

The stabilization and inclination correction part (the stabilization andinclination correction apparatus) of the photographic apparatus 1comprises a correction button 14, a correction switch 14 a, a display17, a CPU 21, a detection unit 25, a driver circuit 29, a correctionunit 30, a hall-sensor signal-processing unit 45, and the camera lens67.

The ON/OFF states of the correction switch 14 a change according to theoperation state of the correction button 14.

Specifically, when the correction button 14 is depressed by theoperator, the correction switch 14 a is changed to the ON state so thatthe stabilization (the translational movement) and inclinationcorrection (the rotational movement), in which the detection unit 25 andthe correction unit 30 are driven independently of the other operationswhich include the photometric operation etc., is carried out at thepredetermined time interval. When the correction switch 14 a is in theON state, (in other words in the correction mode), the correctionparameter SR is set to 1 (SR=1). When the correction switch 14 a is notin the ON state, (in other words in the non-correction mode), thecorrection parameter SR is set to 0 (SR=0). In the embodiment, the valueof the predetermined time interval is set to 1 ms.

The various output commands corresponding to the input signals of theseswitches are controlled by the CPU 21.

The information indicating whether the photometric switch 12 a is in theON state or OFF state is input to port P12 of the CPU 21 as a 1-bitdigital signal. The information indicating whether the shutter releaseswitch 13 a is in the ON or OFF state is input to port P13 of the CPU 21as a 1-bit digital signal. Likewise, the information indicating whetherthe correction switch 14 a is in the ON or OFF state is input to portP14 of the CPU 21 as a 1-bit digital signal.

The AE unit 23 is connected to port P4 of the CPU 21 for inputting andoutputting signals. The AF unit 24 is connected to port P5 of the CPU 21for inputting and outputting signals. The display 17 is connected toport P6 of the CPU 21 for inputting and outputting signals.

Next, the details of the input and output relationships between the CPU21 and the detection unit 25, the driver circuit 29, the correction unit30, and the hall-sensor signal-processing unit 45 are explained.

The detection unit 25 has a first angular velocity sensor 26 a, a secondangular velocity sensor 26 b, an acceleration sensor 26 c, a firsthigh-pass filter circuit 27 a, a second high-pass filter circuit 27 b, afirst amplifier 28 a, a second amplifier 28 b, a third amplifier 28 c,and a fourth amplifier 28 d.

The first angular velocity sensor 26 a detects the angular velocity ofrotary motion of the photographic apparatus 1 around the axis of the ydirection (the yaw). In other words, the first angular velocity sensor26 a is a gyro sensor that detects the yaw angular velocity.

The second angular velocity sensor 26 b detects the angular velocity ofrotary motion of the photographic apparatus 1 around the axis of the xdirection (the pitch). In other words, the second angular velocitysensor 26 b is a gyro sensor that detects the pitch angular velocity.

The acceleration sensor 26 c detects a first gravitational component anda second gravitational component. The first gravitational component isthe horizontal component of gravitational acceleration in the xdirection. The second gravitational component is the vertical componentof gravitational acceleration in the y direction.

The first high-pass filter circuit 27 a reduces the low-frequencycomponent of the signal output from the first angular velocity sensor 26a, because the low-frequency component of the signal output from thefirst angular velocity sensor 26 a includes signal elements that arebased on null voltage and panning motion, neither of which are relatedto hand shake.

Similarly, the second high-pass filter circuit 27 b reduces thelow-frequency component of the signal output from the second angularvelocity sensor 26 b, because the low-frequency component of the signaloutput from the second angular velocity sensor 26 b includes signalelements that are based on null voltage and panning motion, neither ofwhich are related to hand shake.

The first amplifier 28 a amplifies the signal representing the yawangular velocity, whose low-frequency component has been reduced, andoutputs the analog signal to the A/D converter A/D 0 of the CPU 21 as afirst angular velocity vx.

The second amplifier 28 b amplifies the signal representing the pitchangular velocity, whose low-frequency component has been reduced, andoutputs the analog signal to the A/D converter A/D 1 of the CPU 21 as asecond angular velocity vy.

The third amplifier 28 c amplifies the signal representing the firstgravitational component output from the acceleration sensor 26 c, andoutputs the analog signal to the A/D converter A/D 2 of the CPU 21 as afirst acceleration ah.

The fourth amplifier 28 d amplifies the signal representing the secondgravitational component output from the acceleration sensor 26 c, andoutputs the analog signal to the A/D converter A/D 3 of the CPU 21 as asecond acceleration av.

The reduction of the low-frequency component is a two-step process. Theprimary part of the analog high-pass filtering is performed first by thefirst and second high-pass filter circuits 27 a and 27 b, followed bythe secondary part of the digital high-pass filtering that is performedby the CPU 21.

The cut-off frequency of the secondary part of the digital high-passfiltering is higher than that of the primary part of the analoghigh-pass filtering.

In the digital high-pass filtering, the value of a first high-passfilter time constant hx and a second high-pass filter time constant hycan be easily changed.

The supply of electric power to the CPU 21 and each part of thedetection unit 25 begins after the PON switch 11 a is set to the ONstate (i.e. when the main power supply is set to the ON state). Thecalculation of a hand-shake quantity (the digital displacement angleKx_(n) and the second digital displacement angle Ky_(n)) and aninclination angle (the third digital displacement angle Kθ_(n)) beginsafter the PON switch 11 a is set to the ON state.

The CPU 21 converts the first angular velocity vx, which is input to theA/D converter A/D 0, to a first digital angular velocity signal Vx_(n)(A/D conversion operation). It also calculates a first digital angularvelocity VVx_(n) by reducing the low-frequency component of the firstdigital angular velocity signal Vx_(n) (the digital high-pass filtering)because the low-frequency component of the first digital angularvelocity signal Vx_(n) includes signal elements that are based on nullvoltage and panning motion, neither of which are related to hand shake.It also calculates a first hand-shake quantity (a first hand-shakedisplacement angle around the y direction: a first digital displacementangle Kx_(n), caused by yaw) by integrating the first digital angularvelocity VVx_(n) (the integration), for the first stabilization.

Similarly, the CPU 21 converts the second angular velocity vy, which isinput to the A/D converter A/D 1, to a second digital angular velocitysignal Vy_(n) (A/D conversion operation). It also calculates a seconddigital angular velocity VVy_(n) by reducing the low-frequency componentof the second digital angular velocity signal Vy_(n) (the digitalhigh-pass filtering) because the low-frequency component of the seconddigital angular velocity signal Vy_(n) includes signal elements that arebased on null voltage and panning motion, neither of which are relatedto hand shake. It also calculates a second hand-shake quantity (a secondhand-shake displacement angle around the x direction: a second digitaldisplacement angle Ky_(n) caused by pitch) by integrating the seconddigital angular velocity VVy_(n) (the integration), for the secondstabilization.

Furthermore, the CPU 21 converts the first acceleration ah, which isinput to the A/D converter A/D 2, to a first digital acceleration signalDah_(n) (A/D conversion operation). It also calculates a first digitalacceleration Aah_(n) by reducing the high-frequency component of thefirst digital acceleration signal Dah_(n) (the digital low-passfiltering) in order to reduce the noise component in the first digitalacceleration signal Dah_(n).

Similarly, the CPU 21 converts the second acceleration av, which isinput to the A/D converter A/D 3, to a second digital accelerationsignal Dav_(n) (A/D conversion operation). It also calculates a seconddigital acceleration Aav_(n) by reducing the high-frequency component ofthe second digital acceleration signal Dav_(n) (the digital low-passfiltering) in order to reduce the noise component in the second digitalacceleration signal Dav_(n).

The CPU 21 also calculates the inclination angle (third digitaldisplacement angle Kθ_(n)) of the photographic apparatus 1, formed byrotation of the photographic apparatus 1 around its optical axis LX, asmeasured with respect to a level plane perpendicular to the direction ofgravitational force, on the basis of the magnitude relation between theabsolute value of the first digital acceleration Aah_(n) and theabsolute value of the second digital acceleration Aav_(n).

The inclination angle (the third digital displacement angle Kθ_(n)) ofthe photographic apparatus 1 changes according to the orientation of thephotographic apparatus 1 and is measured with respect to one of thefirst horizontal orientation, the second horizontal orientation, thefirst vertical orientation, and the second vertical orientation.Therefore, the inclination angle of the photographic apparatus 1 isrepresented by the angle at which the x direction or the y directionintersects a level plane.

When one of the x direction and the y direction intersects a level planeat an angle of 0 degrees, and when the other of the x direction and they direction intersects a level plane at an angle of 90 degrees, thephotographic apparatus 1 is in a non-inclined state.

Thus, the CPU 21 and the detection unit 25 have a function forcalculating the hand-shake quantity (the first and second hand-shakequantities) and the inclination angle.

The first digital acceleration Aah_(n) (the first gravitationalcomponent) and the second digital acceleration Aav_(n) (the secondgravitational component) change according to the orientation of thephotographic apparatus 1, and take values from −1 to +1.

For example, when the photographic apparatus 1 is held in the firsthorizontal orientation, in other words, when the photographic apparatus1 is held horizontally and the upper surface of the photographicapparatus 1 faces upward (see FIG. 2), the first digital accelerationAah_(n) is 0 and the second digital acceleration Aav_(n) is +1.

When the photographic apparatus 1 is held in the second horizontalorientation, in other words, when the photographic apparatus 1 is heldhorizontally and the lower surface of the photographic apparatus 1 facesupward (see FIG. 9), the first digital acceleration Aah_(n) is 0 and thesecond digital acceleration Aav_(n) is −1.

When the photographic apparatus 1 is held in the first verticalorientation, in other words, when the photographic apparatus 1 is heldvertically and one of the side surfaces of the photographic apparatus 1faces upward (see FIG. 10), the first digital acceleration Aah_(n) is +1and the second digital acceleration Aav_(n) is 0.

When the photographic apparatus 1 is held in the second verticalorientation, in other words, when the photographic apparatus 1 is heldvertically and the other side surface of the photographic apparatus 1faces upward (see FIG. 11), the first digital acceleration Aah_(n) is −1and the second digital acceleration Aav_(n) is 0.

When the front surface of the photographic apparatus 1 faces thedirection of gravitational force or the opposite direction, in otherwords, when the front surface of the photographic apparatus 1 facesupward or downward, the first digital acceleration Aah_(n) and thesecond digital acceleration Aav_(n) are 0.

When the photographic apparatus 1 is rotated (inclined) at an angleKθ_(n) in a counter-clockwise direction viewed from the front, from thefirst horizontal orientation (see FIG. 12), the first digitalacceleration Aah_(n) is +sin(Kθ_(n)) and the second digital accelerationAav_(n) is +cos(Kθ_(n)).

Therefore, the inclination angle (the third digital displacement angleKθ_(n)) can be calculated by performing an arcsine transformation on thefirst digital acceleration Aah_(n) or by performing an arccosinetransformation on the second digital acceleration Aav_(n).

However, while the absolute value of the inclination angle (the thirddigital displacement angle Kθ_(n)) is very small, in other words, nearly0, the variation of the sine function is larger than that of the cosinefunction so that the inclination angle is best calculated by using thearcsine transformation rather than the arccosine transformation(Kθ_(n)=+Sin⁻¹(Aah_(n)), see step S76 in FIG. 8).

When the photographic apparatus 1 is rotated (inclined) at an angleKθ_(n) in a counter-clockwise direction viewed from the front, from thefirst vertical orientation (see FIG. 13), the first digital accelerationAah_(n) is +cos(Kθ_(n)) and the second digital acceleration Aav_(n) is−sin(Kθ_(n)).

Therefore, the inclination angle (the third digital displacement angleKθ_(n)) can be calculated by performing an arccosine transformation onthe first digital acceleration Aah_(n) or by performing an arcsinetransformation on the second digital acceleration Aav_(n) and taking thenegative.

However, while the absolute value of the inclination angle (the thirddigital displacement angle Kθ_(n)) is very small, in other words, nearly0, the variation of the sine function is larger than that of the cosinefunction so that the inclination angle is best calculated by using thearcsine transformation rather than the arccosine transformation(Kθ_(n)=−Sin⁻¹(Aav_(n)), see step S73 in FIG. 8).

When the photographic apparatus 1 is rotated (inclined) at an angleKθ_(n) in a counter-clockwise direction viewed from the front, from thesecond horizontal orientation (see FIG. 14), the first digitalacceleration Aah_(n) is −sin(Kθ_(n)) and the second digital accelerationAav_(n) is −cos(Kθ_(n)).

Therefore, the inclination angle (the third digital displacement angleKθ_(n)) can be calculated by performing an arcsine transformation on thefirst digital acceleration Aah_(n) and taking the negative or byperforming an arccosine transformation on the second digitalacceleration Aav_(n) and taking the negative.

However, while the absolute value of the inclination angle (the thirddigital displacement angle Kθ_(n)) is very small, in other words, nearly0, the variation of the sine function is larger than that of the cosinefunction so that the inclination angle is best calculated by using thearcsine transformation rather than the arccosine transformation(Kθ_(n)=−Sin⁻¹(Aah_(n)), see step S77 in FIG. 8).

When the photographic apparatus 1 is rotated (inclined) at an angleKθ_(n) in a counter-clockwise direction viewed from the front, from thesecond vertical orientation (see FIG. 15), the first digitalacceleration Aah_(n) is −cos(Kθ_(n)) and the second digital accelerationAav_(n) is +sin(Kθ_(n)).

Therefore, the inclination angle (the third digital displacement angleKθ_(n)) can be calculated by performing an arccosine transformation onthe first digital acceleration Aah_(n) and taking the negative or byperforming an arcsine transformation on the second digital accelerationAav_(n).

However, while the absolute value of the inclination angle (the thirddigital displacement angle Kθ_(n)) is very small, in other words, isnearly 0, the variation of the sine function is larger than that of thecosine function so that the inclination angle is best calculated byusing the arcsine transformation rather than the arccosinetransformation (Kθ_(n)=+Sin⁻¹(Aav_(n)), see step S74 in FIG. 8).

When the front surface of the photographic apparatus 1 faces mostlyupward or downward, the first digital acceleration Aah_(n) and thesecond digital acceleration Aav_(n) are nearly 0. In this case, thismeans that inclination correction, in other words, the rotationalmovement in accordance with the inclination angle, is not necessary, itis desirable to perform the stabilization and inclination correctionwith the inclination angle being minimal.

However, when the arccosine transformation on the first digitalacceleration Aah_(n) or the second digital acceleration Aav_(n) that isnearly 0 is performed, the absolute value of the inclination angle (thethird digital displacement angle Kθ_(n)) is a large value. In this case,the stabilization and inclination correction is performed with theinclination angle being large, even when the rotational movement inaccordance with the inclination angle is not necessary. Therefore, theinclination correction cannot be performed correctly.

Therefore, in order to eliminate the inclination angle, it is necessaryto determine whether the front surface of the photographic apparatus 1faces mostly upward or downward using an additional determinationfactor.

An example of the additional determination factor is the determinationof whether the sum of the absolute value of the first digitalacceleration Aah_(n) and the absolute value of the second digitalacceleration Aav_(n) is less than a threshold value.

On the other hand, when the arcsine transformation on the first digitalacceleration Aah_(n) or the second digital acceleration Aav_(n) that isnearly 0 is performed, the absolute value of the inclination angle (thethird digital displacement angle Kθ_(n)) is a small value (nearly 0). Inthis case, the stabilization and inclination correction can beperformed, with the inclination angle being small. Therefore, it is notnecessary to determine whether the front surface of the photographicapparatus 1 faces mostly upward or downward by using the additionaldetermination factor.

The value “n” is an integer greater than or equal to 0, and indicatesthe duration in milliseconds from the point when the timer interruptprocess commences, (t=0, and see step S11 in FIG. 4), to when the lastinterrupt process of the timer is performed (t=n).

In the digital high-pass filtering regarding the yaw, the first digitalangular velocity VVx_(n) is calculated by dividing the sum of the firstdigital angular velocity VVx₀ and VVx_(n-1) (calculated by the timerinterrupt process before the 1 ms predetermined time interval, beforethe last timer interrupt process is performed) by the first high-passfilter time constant hx, and then subtracting the resulting quotientfrom the first digital angular velocity signal Vx_(n)(VVx_(n)=Vx_(n)−(ΣVVx_(n-1))÷hx, see (1) in FIG. 6).

In the digital high-pass filtering regarding the pitch, the seconddigital angular velocity VVy_(n) is calculated by dividing the sum ofthe second digital angular velocity VVy₀ and VVy_(n-1) (calculated bythe timer interrupt process before the 1 ms predetermined time interval,before the last timer interrupt process is performed) by the secondhigh-pass filter time constant hy, and then subtracting the resultingquotient from the second digital angular velocity signal Vy_(n)(VVy_(n)=Vy_(n)−(ΣVVy_(n-1))÷hy, see (1) in FIG. 6).

In the integration regarding the yaw, the first digital displacementangle Kx_(n) is calculated by summing the first digital angular velocityVVx₀ at the point when the timer interrupt process commences, t=0, (seestep S11 in FIG. 4) and the first digital angular velocity VVx_(n) atthe point when the last timer interrupt process is performed (t=n),(Kx_(n)=ΣVVx_(n), see (7) in FIG. 6).

Similarly, in the integration regarding the pitch, the second digitaldisplacement angle Ky_(n), is calculated by summing the second digitalangular velocity VVy₀ at the point when the timer interrupt processcommences and the second digital angular velocity VVy_(n) at the pointwhen the last timer interrupt process is performed (Ky_(n)=ΣVVy_(n), see(7) in FIG. 6).

The inclination angle, in other words, the third digital displacementangle Kθ_(n) is calculated by performing the arcsine transformation onthe smaller of the absolute value of the first digital accelerationAah_(n) and the absolute value of the second digital accelerationAav_(n) and by adding a positive or negative sign(Kθ_(n)=+Sin⁻¹(Aah_(n)), −Sin⁻¹(Aah_(n)), +Sin⁻¹(Aav_(n)), or−Sin⁻¹(Aav_(n)), see (8) in FIG. 6).

Whether the positive or negative sign is added is determined on thebasis of the larger of the absolute value of the first digitalacceleration Aah_(n) and the absolute value of the second digitalacceleration Aav_(n), and the sign of that larger value without applyingthe absolute value (see steps S72 and S75 in FIG. 8).

In the embodiment, the angular velocity and acceleration detectionoperation during the timer interrupt process includes a process in thedetection unit 25 and the input of the first angular velocity vx, thesecond angular velocity vy, the first acceleration ah, and the secondacceleration av from the detection unit 25 to the CPU 21.

In the calculation of the third digital displacement angle Kθ_(n), anintegration is not performed because it is unnecessary. Therefore, theDC offset does not affect the calculation of the third digitaldisplacement angle Kθ_(n), so the inclination angle can be calculatedaccurately.

When the integration including the DC offset is used, the third digitaldisplacement angle Kθ_(n) represents an unspecified value even if theinclination angle is 0. Accordingly, the movable platform 30 a includingthe imager 39 a 1 is rotated (inclined) compared to the initial state inorder to correct the third digital displacement angle Kθ_(n)representing the unspecified value.

Because the displacement of the movable platform 30 a in this case meansthe inclination of the imager 39 a 1, the captured image displayed onthe display 17 is inclined. When the operator sees the inclined image onthe display 17, the operator must visually detect the inclination of thedisplayed image even if the inclination is very small.

However, in the embodiment, because the DC offset does not exist, theinclination of the imager 39 a 1 caused by the DC offset does not exist.

The CPU 21 calculates the position S_(n) where the imaging unit 39 a(the movable platform 30 a) should be moved, in accordance with thehand-shake quantity (the first and second digital displacement anglesKx_(n) and Ky_(n)) and the inclination angle (the third digitaldisplacement angle Kθ_(n)) calculated for the x direction, the ydirection, and the rotational direction, based on the lens coefficient Fand the hall sensor distance coefficient HSD (Sx_(n)=F×tan(Kx_(n)),Sy_(n)=F×tan(Ky_(n)), and Sθ_(n)=HSD÷2×sin(Kθ_(n))). In thiscalculation, both the translational (linear) movement of the movableplatform 30 a in the xy plane and the rotational movement of the movableplatform 30 a in the xy plane are considered.

The horizontal direction component of the position S_(n) is defined asSx_(n), the vertical direction component of the position S_(n) isdefined as Sy_(n), and the rotational (inclination) direction componentof the position S_(n) is defined as Sθ_(n).

The rotation of the movable platform 30 a is performed by applyingdifferent forces in the y direction on a first driving point and asecond driving point on the movable platform 30 a. The movement of themovable platform 30 a in the y direction is performed by applying thesame driving forces in the y direction on the first and second drivingpoints on the movable platform 30 a. The first driving point is thepoint to which a first vertical electro-magnetic force based on thefirst vertical coil 32 a 1 is applied. The second driving point is thepoint to which a second vertical electro-magnetic force based on thesecond vertical coil 32 a 2 is applied. The first driving point is setto a position close to the first vertical hall sensor hv1. The seconddriving point is set to a position close to the second vertical hallsensor hv2.

The first vertical direction component of the first driving pointcorresponding to the position S_(n) is defined as Syl_(n). The secondvertical direction component of the second driving point correspondingto the position S_(n) is defined as Syr_(n).

The first vertical direction component of the first driving point,Syl_(n), and the second vertical direction component of the seconddriving point, Syr_(n), are calculated on the basis of the verticaldirection component of the position S_(n), Sy_(n), and the rotationaldirection component of the position S_(n), Sθ_(n),(Syl_(n)=Sy_(n)+Sθ_(n), Syr_(n)=Sy_(n)−Sθ_(n), see (4) in FIG. 6).

The calculations of the first digital displacement angle Kx_(n), thesecond digital displacement angle Ky_(n), the horizontal directioncomponent of the position S_(n), Sx_(n), the vertical directioncomponent of the position S_(n), Sy_(n), the rotational directioncomponent of the position S_(n), Sθ_(n), the first vertical directioncomponent of the first driving point, Syl_(n), and the second verticaldirection component of the second driving point, Syr_(n) are performedonly when the correction parameter SR is set to 1 and the holding stateparameter HND is set to 1, and during the release-sequence operation(see steps S63, S65, and S66 of FIG. 5). The release-sequence operationcommences after the shutter release button 13 is fully depressed and theshutter release switch 13 a is set to the ON state, and does not finishuntil the release-state parameter RP is set to 0.

In this case, the third digital displacement angle Kθ_(n) is set to 0with the inclination of the photographic apparatus 1 not occurring(Kθ_(n)=0, see step S64 in FIG. 5).

The calculations of the third digital displacement angle Kθ_(n), thehorizontal direction component of the position S_(n), Sx_(n), thevertical direction component of the position S_(n), Sy_(n), therotational direction component of the position S_(n), Sθ_(n), the firstvertical direction component of the first driving point, Syl_(n), andthe second vertical direction component of the second driving point,Syr_(n) are performed only when the correction parameter SR is set to 1and the holding state parameter HND is set to 0, and during therelease-sequence operation (see steps S61, S65, and S66 of FIG. 5).

In this case, the first digital displacement angle Kx_(n) and the seconddigital displacement angle Ky_(n) are set to 0 with the hand shakecaused by yaw and pitch of the photographic apparatus 1 not occurring(Kx_(n)=Ky_(n)=0, see step S62 in FIG. 5).

When the stabilization and inclination correction is not performed(SR=0) and during the release sequence operation (RP=1), the positionS_(n) (Sx_(n), Syl_(n), Syr_(n)) where the movable platform 30 a shouldbe moved is set to the initial state (see step S59 in FIG. 5,Sx_(n)=Syl_(n)=Syr_(n)=0).

While the release-state parameter RP is set to 0, in other words, exceptfor during the release sequence operation, the calculations of the firstdigital displacement angle Kx_(n), the second digital displacement angleKy_(n), the third digital displacement angle Kθ_(n), the horizontaldirection component of the position S_(n), Sx_(n), the verticaldirection component of the position S_(n), Sy_(n), the rotationaldirection component of the position S_(n), Sθ_(n), the first verticaldirection component of the first driving point, Syl_(n), and the secondvertical direction component of the second driving point, Syr_(n) arenot performed. Therefore, in this case, driving of the movable platform30 a is not performed (see step S57 in FIG. 5).

The movement of the movable platform 30 a, which includes the imagingunit 39 a, is performed by using an electromagnetic force and isdescribed later.

The driving force D_(n) is for driving the driver circuit 29 in order tomove the movable platform 30 a to the position S_(n).

The horizontal direction component of the driving force D_(n) for thefirst and second horizontal coils 31 a 1 and 31 a 2 is defined as thehorizontal driving force Dx_(n) (after D/A conversion, the horizontalPWM duty dx).

The vertical direction component of the driving force D_(n) for thefirst vertical coil 32 a 1 is defined as the first vertical drivingforce Dyl_(n) (after D/A conversion, the first vertical PWM duty dyl).

The vertical direction component of the driving force D_(n) for thesecond vertical coil 32 a 2 is defined as the second vertical drivingforce Dyr_(n) (after D/A conversion, the second vertical PWM duty dyr).

The correction unit 30 is an apparatus that corrects for the effects ofhand shake by moving the imaging unit 39 a to the position S_(n), bycanceling the lag of the subject image on the imaging surface of theimager 39 a 1 of the imaging unit 39 a, and by stabilizing the subjectimage displayed on the imaging surface of the imager 39 a 1.

The correction unit 30 has a fixed unit 30 b and a movable platform 30 athat includes the imaging unit 39 a and can be moved in the xy plane.

By moving the movable platform 30 a in the x direction, the firststabilization for correcting the hand shake caused by yaw, which is thefirst hand-shake displacement angle around the y direction, isperformed; and by moving the movable platform 30 a in the y direction,the second stabilization for correcting the hand shake caused by pitch,which is the second hand-shake displacement angle around the xdirection, is performed (the translational movement).

Moreover, the correction unit 30 performs the inclination correction(the rotational movement) that corrects (reduces) the inclination of thephotographic apparatus 1 formed by rotation of the photographicapparatus 1 around its optical axis LX, as measured with respect to alevel plane perpendicular to the direction of gravitational force, byrotating the movable platform 30 a including the imaging unit 39 aaround an axis parallel to the optical axis LX.

In other words, in the inclination correction, the movement controlrepositions the movable platform 30 a so that the upper and lower sidesof the rectangle composing the outline of the imaging surface of theimager 39 a 1 are perpendicular to the direction of gravitational forceand the left and right sides are parallel to the direction ofgravitational force.

Therefore, the imager 39 a 1 can be automatically leveled without usinga level vial. When the photographic apparatus 1 images a subjectincluding the horizon, the imaging operation can be performed, with theupper and lower sides of the rectangle composing the outline of theimaging surface of the imager 39 a 1 being parallel to the horizon.

Moreover, due to the inclination correction, the upper and lower sidesof the rectangle composing the outline of the imaging surface of theimager 39 a 1 are kept perpendicular to the direction of gravitationalforce, and the left and right sides of the rectangle composing theoutline of the imaging surface of the imager 39 a 1 are kept parallel tothe direction of gravitational force. Therefore, hand shake caused byroll is also corrected by the inclination correction. In other words,rotating the movable platform 30 a in the xy plane for the inclinationcorrection also achieves a third stabilization for correcting the handshake caused by roll.

When the stabilization and inclination correction is not performed(SR=0), in other words, when the photographic apparatus 1 is not in thecorrection mode, the position S_(n) (Sx_(n), Syl_(n), Syr_(n)) where themovable platform 30 a should be moved is set to the predeterminedposition. In the embodiment, the predetermined position is the center ofits movement range.

Driving of the movable platform 30 a, including movement to the fixed(held) position of the initial state, is performed by theelectro-magnetic force of the coil unit and the magnetic unit throughthe driver circuit 29, which has the horizontal PWM duty dx input fromthe PWM 0 of the CPU 21, the first vertical PWM duty dyl input from thePWM 1 of the CPU 21, and the second vertical PWM duty dyr input from thePWM 2 of the CPU 21 (see (6) in FIG. 6).

The detected-position P_(n) of the movable platform 30 a, either beforeor after the movement effected by the driver circuit 29, is detected bythe hall sensor unit 44 a and the hall-sensor signal-processing unit 45.

Information regarding the horizontal direction component of thedetected-position P_(n), in other words, the horizontaldetected-position signal px, is input to the A/D converter A/D 4 of theCPU 21 (see (2) in FIG. 6). The horizontal detected-position signal pxis an analog signal that is converted to a digital signal by the A/Dconverter A/D 4 (A/D conversion operation). The horizontal directioncomponent of the detected-position P_(n) after the A/D conversionoperation, is defined as pdx_(n) and corresponds to the horizontaldetected-position signal px.

Information regarding one of the vertical direction components of thedetected-position P_(n), in other words, the first verticaldetected-position signal pyl, is input to the A/D converter A/D 5 of theCPU 21. The first vertical detected-position signal pyl is an analogsignal that is converted to a digital signal by the A/D converter A/D 5(A/D conversion operation). The first vertical direction component ofthe detected-position P_(n) after the A/D conversion operation isdefined as pdyl_(n) and corresponds to the first verticaldetected-position signal pyl.

Information regarding the other of the vertical direction components ofthe detected-position P_(n), in other words, the second verticaldetected-position signal pyr, is input to the A/D converter A/D 6 of theCPU 21. The second vertical detected-position signal pyr is an analogsignal that is converted to a digital signal by the A/D converter A/D 6(A/D conversion operation). The second vertical direction component ofthe detected-position P_(n) after the A/D conversion operation isdefined as pdyr_(n) and corresponds to the second verticaldetected-position signal pyr.

The PID (Proportional Integral Differential) control calculates thehorizontal driving force Dx_(n) and the first and second verticaldriving forces Dyl_(n) and Dyr_(n) on the basis of the coordinate datafor the detected-position P_(n) (pdx_(n), pdyl_(n), pdyr_(n)) and theposition S_(n) (Sx_(n), Syl_(n), Syr_(n)) following movement (see (5) inFIG. 6).

Driving of the movable platform 30 a to the position S_(n) (Sx_(n),Syl_(n), Syr_(n)) corresponding to the stabilization and inclinationcorrection of the PID control, is performed when the photographicapparatus 1 is in the correction mode (SR=1) where the correction switch14 a is set to the ON state and when the release-state parameter RP isset to 1 (RP=1).

When the correction parameter SR is 0 and the release-state parameter RPis set to 1, PID control unrelated to the stabilization and inclinationcorrection is performed so that the movable platform 30 a is moved tothe predetermined position (the center of the movement range) at theinitial state such that each of the four sides composing the outline ofthe imaging surface of the imager 39 a 1 of the imaging unit 39 a isparallel to either the x direction or the y direction, in other words,such that the movable platform 30 a is not rotated (inclined).

The movable platform 30 a has a coil unit for driving that is comprisedof a first horizontal coil 31 a 1, a second horizontal coil 31 a 2, afirst vertical coil 32 a 1, and a second vertical coil 32 a 2, animaging unit 39 a having the imager 39 a 1, and a hall sensor unit 44 aas a magnetic-field change-detecting element unit (see FIG. 7). In theembodiment, the imager 39 a 1 is a CCD; however, the imager 39 a 1 maybe of another type, such as a CMOS, etc.

The fixed unit 30 b has a magnetic position detection and driving unitthat is comprised of a first horizontal magnet 411 b 1, a secondhorizontal magnet 411 b 2, a first vertical magnet 412 b 1, a secondvertical magnet 412 b 2, a first horizontal yoke 431 b 1, a secondhorizontal yoke 431 b 2, a first vertical yoke 432 b 1, and a secondvertical yoke 432 b 2.

The fixed unit 30 b movably and rotatably supports the movable platform30 a in the rectangular-shaped movement range in the xy plane, usingballs, etc. The balls are arranged between the fixed unit 30 b and themovable platform 30 a.

When the central area of the imager 39 a 1 is intersecting the opticalaxis LX of the camera lens 67, the relationship between the position ofthe movable platform 30 a and the position of the fixed unit 30 b isarranged so that the movable platform 30 a is positioned at the centerof its movement range in both the x direction and the y direction, inorder to utilize the full size of the imaging range of the imager 39 a1.

The rectangular form of the imaging surface of the imager 39 a 1 has twodiagonal lines. In the embodiment, the center of the imager 39 a 1 is atthe intersection of these two diagonal lines.

Furthermore, the movable platform 30 a is positioned at the center ofits movement range in both the x direction and the y direction, and eachof the four sides composing the outline of the imaging surface of theimager 39 a 1 is parallel to either the x direction or the y direction,in the initial state immediately after the shutter release switch 13 ais set to the ON state so that the release sequence operation commences(see step S21 of FIG. 4). Then, the stabilization and inclinationcorrection commences.

The first horizontal coil 31 a 1, the second horizontal coil 31 a 2, thefirst vertical coil 32 a 1, the second vertical coil 32 a 2, and thehall sensor unit 44 a are attached to the movable platform 30 a.

The first horizontal coil 31 a 1 forms a seat and a spiral-shaped coilpattern. The coil pattern of the first horizontal coil 31 a 1 has lineswhich are parallel to the y direction, thus creating the firsthorizontal electro-magnetic force to move the movable platform 30 a thatincludes the first horizontal coil 31 a 1, in the x direction.

The first horizontal electro-magnetic force is created by the currentdirection of the first horizontal coil 31 a 1 and the magnetic-fielddirection of the first horizontal magnet 411 b 1.

The second horizontal coil 31 a 2 forms a seat and a spiral-shaped coilpattern. The coil pattern of the second horizontal coil 31 a 2 has lineswhich are parallel to the y direction, thus creating the secondhorizontal electromagnetic force to move the movable platform 30 a thatincludes the second horizontal coil 31 a 2, in the x direction.

The second horizontal electromagnetic force is created by the currentdirection of the second horizontal coil 31 a 2 and the magnetic-fielddirection of the second horizontal magnet 411 b 2.

The first vertical coil 32 a 1 forms a seat and a spiral-shaped coilpattern. The coil pattern of the first vertical coil 32 a 1 has lineswhich are parallel to the x direction, thus creating the first verticalelectromagnetic force to move the movable platform 30 a that includesthe first vertical coil 32 a 1, in the y direction and to rotate themovable platform 30 a.

The first vertical electro-magnetic force is created by the currentdirection of the first vertical coil 32 a 1 and the magnetic-fielddirection of the first vertical magnet 412 b 1.

The second vertical coil 32 a 2 forms a seat and a spiral-shaped coilpattern. The coil pattern of the second vertical coil 32 a 2 has lineswhich are parallel to the x direction, thus creating the second verticalelectromagnetic force to move the movable platform 30 a that includesthe second vertical coil 32 a 2, in the y direction and to rotate themovable platform 30 a.

The second vertical electromagnetic force is created by the currentdirection of the second vertical coil 32 a 2 and the magnetic-fielddirection of the second vertical magnet 412 b 2.

The first and second horizontal coils 31 a 1 and 31 a 2 and the firstand second vertical coils 32 a 1 and 32 a 2 are connected to the drivercircuit 29, which drives the first and second horizontal coils 31 a 1and 31 a 2 and the first and second vertical coils 32 a 1 and 32 a 2,through the flexible circuit board (not depicted).

The horizontal PWM duty dx, that is a duty ratio of a PWM pulse, isinput to the driver circuit 29 from the PWM 0 of the CPU 21. The firstvertical PWM duty dyl, that is a duty ratio of a PWM pulse, is input tothe driver circuit 29 from the PWM 1 of the CPU 21. The second verticalPWM duty dyr, that is a duty ratio of a PWM pulse, is input to thedriver circuit 29 from the PWM 2 of the CPU 21.

The driver circuit 29 supplies the same power to the first and secondhorizontal coils 31 a 1 and 31 a 2, corresponding to the value of thehorizontal PWM duty dx, to move the movable platform 30 a in the xdirection.

The driver circuit 29 supplies power to the first vertical coil 32 a 1corresponding to the value of the first vertical PWM duty dyl and to thesecond vertical coil 32 a 2 corresponding to the value of the secondvertical PWM duty dyr, in order to move the movable platform 30 a in they direction and to rotate the movable platform 30 a.

The positional relationship between the first and second horizontalcoils 31 a 1 and 31 a 2 is determined so that the optical axis LX islocated between the first and second horizontal coils 31 a 1 and 31 a 2in the x direction, in the initial state. In other words, the first andsecond horizontal coils 31 a 1 and 31 a 2 are arranged in a symmetricalarrangement centered on the optical axis LX, in the x direction in theinitial state.

The first and second vertical coils 32 a 1 and 32 a 2 are arranged inthe x direction in the initial state.

The first and second horizontal coils 31 a 1 and 31 a 2 are arrangedsuch that the distance between the central area of the imager 39 a 1 andthe central area of the first horizontal coil 31 a 1 in the x directionis the same as the distance between the center of the imager 39 a 1 andthe central area of the second horizontal coil 31 a 2 in the xdirection.

The first and second vertical coils 32 a 1 and 32 a 2 are arranged suchthat in the initial state, the distance between the central area of theimager 39 a 1 and the central area of the first vertical coil 32 a 1 inthe y direction is the same as the distance between the center of theimager 39 a 1 and the central area of the second vertical coil 32 a 2 inthe y direction.

The first horizontal magnet 411 b 1 is attached to the movable platformside of the fixed unit 30 b, where the first horizontal magnet 411 b 1faces the first horizontal coil 31 a 1 and the horizontal hall sensorhh10 in the z direction.

The second horizontal magnet 411 b 2 is attached to the movable platformside of the fixed unit 30 b, where the second horizontal magnet 411 b 2faces the second horizontal coil 31 a 2 in the z direction.

The first vertical magnet 412 b 1 is attached to the movable platformside of the fixed unit 30 b, where the first vertical magnet 412 b 1faces the first vertical coil 32 a 1 and the first vertical hall sensorhv1 in the z direction.

The second vertical magnet 412 b 2 is attached to the movable platformside of the fixed unit 30 b, where the second vertical magnet 412 b 2faces the second vertical coil 32 a 2 and the second vertical hallsensor hv2 in the z direction.

The first horizontal magnet 411 b 1 is attached to the first horizontalyoke 431 b 1, such that the N pole and S pole are arranged in the xdirection. The first horizontal yoke 431 b 1 is attached to the fixedunit 30 b.

Likewise, the second horizontal magnet 411 b 2 is attached to the secondhorizontal yoke 431 b 2, such that the N pole and S pole are arranged inthe x direction. The second horizontal yoke 431 b 2 is attached to thefixed unit 30 b.

The first vertical magnet 412 b 1 is attached to the first vertical yoke432 b 1, such that the N pole and S pole are arranged in the ydirection. The first vertical yoke 432 b 1 is attached to the fixed unit30 b.

Likewise, the second vertical magnet 412 b 2 is attached to the secondvertical yoke 432 b 2, such that the N pole and S pole are arranged inthe y direction. The second vertical yoke 432 b 2 is attached to thefixed unit 30 b.

The first and second horizontal yokes 431 b 1 and 431 b 2 are made of asoft magnetic material.

The first horizontal yoke 431 b 1 prevents the magnetic field of thefirst horizontal magnet 411 b 1 from dissipating to the surroundings,and raises the magnetic-flux density between the first horizontal magnet411 b 1 and the first horizontal coil 31 a 1, and between the firsthorizontal magnet 411 b 1 and the horizontal hall sensor hh10.

Similarly, the second horizontal yoke 431 b 2 prevents the magneticfield of the second horizontal magnet 411 b 2 from dissipating to thesurroundings, and raises the magnetic-flux density between the secondhorizontal magnet 411 b 2 and the second horizontal coil 31 a 2.

The first and second vertical yokes 432 b 1 and 432 b 2 are made of asoft magnetic material.

The first vertical yoke 432 b 1 prevents the magnetic field of the firstvertical magnet 412 b 1 from dissipating to the surroundings, and raisesthe magnetic-flux density between the first vertical magnet 412 b 1 andthe first vertical coil 32 a 1, and between the first vertical magnet412 b 1 and the first vertical hall sensor hv1.

Likewise, the second vertical yoke 432 b 2 prevents the magnetic fieldof the second vertical magnet 412 b 2 from dissipating to thesurroundings, and raises the magnetic-flux density between the secondvertical magnet 412 b 2 and the second vertical coil 32 a 2, and betweenthe second vertical magnet 412 b 2 and the second vertical hall sensorhv2.

The first and second horizontal yokes 431 b 1 and 431 b 2 and the firstand second vertical yokes 432 b 1 and 432 b 2 may be composed of onebody or separate bodies.

The hall sensor unit 44 a is a one-axis hall sensor with three componenthall sensors that are electromagnetic converting elements(magnetic-field change-detecting elements) using the Hall Effect. Thehall sensor unit 44 a detects the horizontal detected-position signalpx, the first vertical detected-position signal pyl, and the secondvertical detected-position signal pyr.

One of the three hall sensors is a horizontal hall sensor hh10 fordetecting the horizontal detected-position signal px, and another of thethree hall sensors is a first vertical hall sensor hv1 for detecting thefirst vertical detected-position signal pyl, with the third being asecond vertical hall sensor hv2 for detecting the second verticaldetected-position signal pyr.

The horizontal hall sensor hh10 is attached to the movable platform 30a, where the horizontal hall sensor hh10 faces the first horizontalmagnet 411 b 1 of the fixed unit 30 b in the z direction.

The horizontal hall sensor hh10 may be arranged outside the spiralwinding of the first horizontal coil 31 a 1 in the y direction. However,it is desirable for the horizontal hall sensor hh10 to be arrangedinside the spiral winding of the first horizontal coil 31 a 1, andmidway along the outer circumference of the spiral winding of the firsthorizontal coil 31 a 1 in the x direction (see FIG. 7).

The horizontal hall sensor hh10 is layered on the first horizontal coil31 a 1 in the z direction. Accordingly, the area in which the magneticfield is generated for the position-detecting operation and the area inwhich the magnetic field is generated for driving the movable platform30 a are shared. Therefore, the length of the first horizontal magnet411 b 1 in the y direction and the length of the first horizontal yoke431 b 1 in the y direction can be shortened.

The first vertical hall sensor hv1 is attached to the movable platform30 a, where the first vertical hall sensor hv1 faces the first verticalmagnet 412 b 1 of the fixed unit 30 b in the z direction.

The second vertical hall sensor hv2 is attached to the movable platform30 a, where the second vertical hall sensor hv2 faces the secondvertical magnet 412 b 2 of the fixed unit 30 b in the z direction.

The first and second vertical hall sensors hv1 and hv2 are arranged inthe x direction in the initial state.

The first vertical hall sensor hv1 may be arranged outside the spiralwinding of the first vertical coil 32 a 1 in the x direction. However,it is desirable for the first vertical hall sensor hv1 to be arrangedinside the spiral winding of the first vertical coil 32 a 1, and midwayalong the outer circumference of the spiral winding of the firstvertical coil 32 a 1 in the y direction.

The first vertical hall sensor hv1 is layered on the first vertical coil32 a 1 in the z direction. Accordingly, the area in which the magneticfield is generated for the position-detecting operation and the area inwhich the magnetic field is generated for driving the movable platform30 a are shared. Therefore, the length of the first vertical magnet 412b 1 in the x direction and the length of the first vertical yoke 432 b 1in the x direction can be shortened.

The second vertical hall sensor hv2 may be arranged outside the spiralwinding of the second vertical coil 32 a 2 in the x direction. However,it is desirable for the second vertical hall sensor hv2 to be arrangedinside the spiral winding of the second vertical coil 32 a 2, and midwayalong the outer circumference of the spiral winding of the secondvertical coil 32 a 2 in the y direction.

The second vertical hall sensor hv2 is layered on the second verticalcoil 32 a 2 in the z direction. Accordingly, the area in which themagnetic field is generated for the position-detecting operation and thearea in which the magnetic field is generated for driving the movableplatform 30 a are shared. Therefore, the length of the second verticalmagnet 412 b 2 in the x direction and the length of the second verticalyoke 432 b 2 in the x direction can be shortened.

Furthermore, the first driving point to which the first verticalelectromagnetic force based on the first vertical coil 32 a 1 is appliedcan be close to a position-detecting point by the first vertical hallsensor hv1, and the second driving point to which the second verticalelectro-magnetic force based on the second vertical coil 32 a 2 isapplied can be close to a position-detecting point by the secondvertical hall sensor hv2. Therefore, accurate driving control of themovable platform 30 a can be performed.

In the initial state, it is desirable for the horizontal hall sensorhh10 to be located at a place on the hall sensor unit 44 a that faces anintermediate area between the N pole and S pole of the first horizontalmagnet 411 b 1 in the x direction, as viewed from the z direction, toperform the position-detecting operation utilizing the full range withinwhich an accurate position-detecting operation can be performed based onthe linear output change (linearity) of the one-axis hall sensor.

Similarly, in the initial state, it is desirable for the first verticalhall sensor hv1 to be located at a place on the hall sensor unit 44 athat faces an intermediate area between the N pole and S pole of thefirst vertical magnet 412 b 1 in the y direction, as viewed from the zdirection.

Likewise, in the initial state, it is desirable for the second verticalhall sensor hv2 to be located at a place on the hall sensor unit 44 athat faces an intermediate area between the N pole and S pole of thesecond vertical magnet 412 b 2 in the y direction, as viewed from the zdirection.

The first hall-sensor signal-processing unit 45 has a signal processingcircuit of the magnetic-field change-detecting element that is comprisedof a first hall-sensor signal-processing circuit 450, a secondhall-sensor signal-processing circuit 460, and a third hall-sensorsignal-processing circuit 470.

The first hall-sensor signal-processing circuit 450 detects a horizontalpotential difference between the output terminals of the horizontal hallsensor hh10, based on the output signal of the horizontal hall sensorhh10.

The first hall-sensor signal-processing circuit 450 outputs thehorizontal detected-position signal px to the A/D converter A/D 4 of theCPU 21, on the basis of the horizontal potential difference. Thehorizontal detected-position signal px represents the location of thepart of the movable platform 30 a which has the horizontal hall sensorhh10, in the x direction.

The first hall-sensor signal-processing circuit 450 is connected to thehorizontal hall sensor hh10 through the flexible circuit board (notdepicted).

The second hall-sensor signal-processing circuit 460 detects a firstvertical potential difference between the output terminals of the firstvertical hall sensor hv1, based on the output signal of the firstvertical hall sensor hv1.

The second hall-sensor signal-processing circuit 460 outputs the firstvertical detected-position signal pyl to the A/D converter A/D 5 of theCPU 21, on the basis of the first vertical potential difference. Thefirst vertical detected-position signal pyl represents the location ofthe part of the movable platform 30 a which has the first vertical hallsensor hv1 (the position-detecting point by the first vertical hallsensor hv1), in the y direction.

The second hall-sensor signal-processing circuit 460 is connected to thefirst vertical hall sensor hv1 through the flexible circuit board (notdepicted).

The third hall-sensor signal-processing circuit 470 detects a secondvertical potential difference between the output terminals of the secondvertical hall sensor hv2, based on the output signal of the secondvertical hall sensor hv2.

The third hall-sensor signal-processing circuit 470 outputs the secondvertical detected-position signal pyr to the A/D converter A/D 6 of theCPU 21, on the basis of the second vertical potential difference. Thesecond vertical detected-position signal pyr represents the location ofthe part of the movable platform 30 a which has the second vertical hallsensor hv2 (the position-detecting point by the second vertical hallsensor hv2), in the y direction.

The third hall-sensor signal-processing circuit 470 is connected to thesecond vertical hall sensor hv2 through the flexible circuit board (notdepicted).

In the embodiment, the three hall sensors (hh10, hv1 and hv2) are usedfor specifying the location of the movable platform 30 a including therotational (inclination) angle.

The locations in the y direction of the two points on the movableplatform 30 a are determined by using two of the three hall sensors (hv1and hv2). The location in the x direction of the one point on themovable platform 30 a is determined by using another of the three hallsensors (hh10). The location of the movable platform 30 a, whichincludes the rotational (inclination) angle in the xy plane, can bedetermined on the basis of the information regarding the locations inthe x direction of the one point and the location in the y direction ofthe two points.

Next, the main operation of the photographic apparatus 1 in theembodiment is explained using the flowchart of FIG. 4.

When the PON switch 11 a is set to the ON state, the electrical power issupplied to the detection unit 25 so that the detection unit 25 is setto the ON state in step S10.

In step S11, the timer interrupt process at the predetermined timeinterval (1 ms) commences. In step S12, the value of the release-stateparameter RP is set to 0. The details of the timer interrupt process inthe embodiment are explained later using the flowchart of FIG. 5. Instep S13, the value of the holding state parameter HND is set to 0.

In step S14, it is determined whether the photometric switch 12 a is setto the ON state. When it is determined that the photometric switch 12 ais not set to the ON state, the operation returns to step S13 and theprocess in steps S13 and S14 is repeated. Otherwise, the operationcontinues on to step S15.

In step S15, it is determined whether the correction switch 14 a is setto the ON state. When it is determined that the correction switch 14 ais not set to the ON state, the value of the correction parameter SR isset to 0 in step S16. Otherwise, the value of the correction parameterSR is set to 1 in step S17.

When the photometric switch 12 a is set to the ON state, the AE sensorof the AE unit 23 is driven, the photometric operation is performed, andthe aperture value and the duration of the exposure operation arecalculated, in step S18.

In step S19, the AF sensor and the lens control circuit of the AF unit24 are driven to perform the AF sensing and focus operations,respectively. Furthermore, the lens information including the lenscoefficient F is communicated from the camera lens 67 to the CPU 21.

In step S20, it is determined whether the shutter release switch 13 a isset to the ON state. When the shutter release switch 13 a is not set tothe ON state, the operation returns to step S13 and the process in stepsS13 to S19 is repeated. Otherwise, the operation continues on to stepS21.

In step S21, the value of the release-state parameter RP is set to 1,and then the release-sequence operation commences, as the initial state.In the initial state, the movable platform 30 a is positioned at thecenter of its movement range in both the x direction and the ydirection, and each of the four sides of the rectangle composing theoutline of the imaging surface of the imager 39 a 1 is parallel toeither the x direction or the y direction.

In step S22, the value of the mirror state parameter MP is set to 1.

In step S23, the mirror-up operation and the aperture closing operationcorresponding to the aperture value that is either preset or calculated,are performed by the mirror-aperture-shutter unit 18.

After the mirror-up operation is finished, the value of the mirror stateparameter MP is set to 0, in step S24. In step S25, the openingoperation of the shutter (the movement of the front curtain of theshutter) commences.

In step S26, the exposure operation, that is, the electric chargeaccumulation of the imager 39 a 1 (CCD etc.), is performed. After theexposure time has elapsed, the closing operation of the shutter (themovement of the rear curtain in the shutter), the mirror-down operation,and the opening operation of the aperture are performed by themirror-aperture-shutter unit 18, in step S27.

In step S28, the value of the release-state parameter RP is set to 0 sothat the photometric switch 12 a and the shutter release switch 13 a areset to the OFF state and the release-sequence operation is finished. Instep S29, the electric charge accumulated in the imager 39 a 1 duringthe exposure time is read. In step S30, the CPU 21 communicates with theDSP 19 so that the image-processing operation is performed based on theelectric charge read from the imager 39 a 1. The image on which theimage-processing operation is performed is stored in the memory of thephotographic apparatus 1. In step S31, the image stored in the memory isdisplayed on the display 17, and the operation then returns to step S13.In other words, the photographic apparatus 1 is returned to a state inwhich the next imaging operation can be performed.

Next, the timer interrupt process in the embodiment, which commences instep S11 in FIG. 4 and is performed at every predetermined time interval(1 ms) independent of the other operations, is explained using theflowchart of FIG. 5.

When the timer interrupt process commences, the first angular velocityvx, which is output from the detection unit 25, is input to the A/Dconverter A/D 0 of the CPU 21 and converted to the first digital angularvelocity signal Vx_(n), in step S51. The second angular velocity vy,which is also output from the detection unit 25, is input to the A/Dconverter A/D 1 of the CPU 21 and converted to the second digitalangular velocity signal Vy_(n) (the angular velocity detectionoperation).

Furthermore, the first acceleration ah, which is also output from thedetection unit 25, is input to the A/D converter A/D 2 of the CPU 21 andconverted to the first digital acceleration signal Dah_(n). Similarly,the second acceleration av, which is also output from the detection unit25, is input to the A/D converter A/D 3 of the CPU 21 and converted tothe second digital acceleration signal Dav_(n) (the accelerationdetection operation).

The low frequencies of the first and second digital angular velocitysignals Vx_(n) and Vy_(n) are reduced in the digital high-pass filtering(the first and second digital angular velocities VVx_(n) and VVy_(n),see (1) in FIG. 6).

The high frequencies of the first and second digital accelerationsignals Dah_(n) and Dav_(n) are reduced in the digital low-passfiltering (the first and second digital acceleration Aah_(n) andAav_(n), see (1) in FIG. 6).

In step S52, the hall sensor unit 44 a detects the position of themovable platform 30 a. The horizontal detected-position signal px andthe first and second vertical detected-position signals pyl and pyr arecalculated by the hall-sensor signal-processing unit 45. The horizontaldetected-position signal px is then input to the A/D converter A/D 4 ofthe CPU 21 and converted to the digital signal pdx_(n), the firstvertical detected-position signal pyl is then input to the A/D converterA/D 5 of the CPU 21 and converted to the digital signal pdyl_(n), andthe second vertical detected-position signal pyr is input to the A/Dconverter A/D 6 of the CPU 21 and also converted to the digital signalpdyr_(n), both of which thus specify the present position P_(n)(pdx_(n), pdyl_(n), pdyr_(n)) of the movable platform 30 a (see (2) inFIG. 6).

In step S53, it is determined whether the value of the release-stateparameter RP is set to 1. When it is determined that the value of therelease-state parameter RP is not set to 1, the operation continues tostep S54, otherwise, the operation proceeds to step S58.

In step S54, it is determined whether the absolute value of the firstdigital angular velocity VVx_(n) is greater than the first thresholdRex. When it is determined that the absolute value of the first digitalangular velocity VVx_(n) is greater than the first threshold Rex, it isdetermined that the photographic apparatus 1 is held by the operator'shand so that the hand shake of the photographic apparatus 1 tends tooccur and the operation proceeds to step S56. Otherwise, the operationcontinues to step S55.

In step S55, it is determined whether the absolute value of the seconddigital angular velocity VVy_(n) is greater than the second thresholdRey. When it is determined that the absolute value of the second digitalangular velocity VVy_(n) is greater than the second threshold Rey, it isdetermined that the photographic apparatus 1 is held by the operator'shand so that the hand shake of the photographic apparatus 1 tends tooccur and the operation continues to step S56. Otherwise, the operationproceeds to step S57.

In step S56, the value of the holding state parameter HND is set to 1.

In step S57, driving the movable platform 30 a is set to the OFF state,in other words, the correction unit 30 is set to a state where thedriving control of the movable platform 30 a is not performed.

In step S58, it is determined whether the value of the correctionparameter SR is 0. When it is determined that the value of thecorrection parameter SR is 0 (SR=0), in other words, that thephotographic apparatus 1 is not in the correction mode, the positionS_(n) (Sx_(n), Syl_(n), Syr_(n)) where the movable platform 30 a shouldbe moved, is set to the initial state (Sx_(n)=Syl_(n)=Syr_(n)=0) in stepS59 (see (4) in FIG. 6).

When it is determined that the value of the correction parameter SR isnot 0 (SR=1), in other words when the photographic apparatus 1 is incorrection mode, the operation continues to step S60.

In step S60, it is determined whether the value of the holding stateparameter HND is set to 0. When it is determined that the value of theholding state parameter HND is set to 0, the operation continues to stepS61 for performing the inclination correction. Otherwise, the operationproceeds to step S63 for performing the first and second stabilizations.

In step S61, the third digital displacement angle Kθ_(n) is calculatedon the basis of the first and second digital accelerations Aah_(n) andAav_(n) (see (8) in FIG. 6).

The details of the calculation of the third digital displacement angleKθ_(n) in the embodiment are explained later using the flowchart of FIG.8.

In step S62, the first digital displacement angle Kx_(n) and the seconddigital displacement angle Ky_(n), are set to 0 with the hand shakecaused by yaw and pitch of the photographic apparatus 1 not occurring(Kx_(n)=Ky_(n)=0) Namely, in this case, the stabilization (the first andsecond stabilizations) is not performed.

In step S63, the first and second digital displacement angles Kx_(n) andKy_(n) are calculated on the basis of the first and second digitalangular velocities VVx_(n) and VVy_(n) (see (7) in FIG. 6).

In step S64, the third digital displacement angle Kθ_(n) is set to 0with the inclination of the photographic apparatus 1 not occurring(Kθ_(n)=0). Namely, in this case, the inclination correction is notperformed.

In step S65, the rotational (inclination) direction component of theposition S_(n), Sθ_(n), is calculated on the basis of the third digitaldisplacement angle Kθ_(n) and the hall sensor distance coefficient HSD(see (3) in FIG. 6).

In step S66, the horizontal direction component of the position S_(n),Sx_(n), and the vertical direction component of the position S_(n),Sy_(n), are calculated on the basis of the first digital displacementangle Kx_(n), the second digital displacement angle Ky_(n), and the lenscoefficient F (see (3) in FIG. 6).

Then, the first vertical direction component of the first driving pointSyl_(n) and the second vertical direction component of the seconddriving point Syr_(n) are calculated on the basis of the verticaldirection component of the position S_(n), Sy_(n), and the rotational(inclination) direction component of the position S_(n), Sθ_(n) (see (4)in FIG. 6).

In step S67, the horizontal driving force Dx_(n) (the horizontal PWMduty dx), the first vertical driving force Dyl_(n) (the first verticalPWM duty dyl), and the second vertical driving force Dyr_(n) (the secondvertical PWM duty dyr) of the driving force D_(n), which moves themovable platform 30 a to the position S_(n), are calculated on the basisof the position S_(n) (Sx_(n), Sy_(n), Sθ_(n)) that was determined instep S59 or step S66, and the present position P_(n) (pdx_(n), pdyl_(n),pdyr_(n)) (see (5) in FIG. 6).

In step S68, the first and second horizontal coils 31 a 1 and 31 a 2 aredriven by applying the horizontal PWM duty dx to the driver circuit 29;the first vertical coil 32 a 1 is driven by applying the first verticalPWM duty dyl to the driver circuit 29; and the second vertical coil 32 a2 is driven by applying the second vertical PWM duty dyr to the drivercircuit 29, so that the movable platform 30 a is moved to position S_(n)(Sx_(n), Sy_(n), Sθ_(n)) (see (6) in FIG. 6).

The process of steps S67 and S68 is an automatic control calculationthat is performed by the PID automatic control for performing general(normal) proportional, integral, and differential calculations.

Next, the calculation of the third digital displacement angle Kθ_(n),which is performed in step S61 in FIG. 5, is explained using theflowchart of FIG. 8.

When the calculation of the third digital displacement angle Kθ_(n)commences, it is determined whether the absolute value of the seconddigital acceleration Aav_(n) is larger than or equal to the absolutevalue of the first digital acceleration Aah_(n), in step S71.

When it is determined that the absolute value of the second digitalacceleration Aav_(n) is larger than or equal to the absolute value ofthe first digital acceleration Aah_(n), the operation proceeds to stepS75, otherwise, the operation continues to step S72.

In step S72, it is determined whether the first digital accelerationAah_(n) is less than 0. When it is determined that the first digitalacceleration Aah_(n) is less than 0, the operation proceeds to step S74,otherwise, the operation continues to step S73.

In step S73, the CPU 21 determines that the photographic apparatus 1 isheld approximately in the first vertical orientation, and calculates theinclination angle (the third digital displacement angle Kθ_(n)) byperforming the arcsine transformation on the second digital accelerationAav_(n) and taking the negative (Kθ_(n)=−Sin⁻¹(Aav_(n))).

In step S74, the CPU 21 determines that the photographic apparatus isheld approximately in the second vertical orientation, and calculatesthe inclination angle (the third digital displacement angle Kθ_(n)) byperforming the arcsine transformation on the second digital accelerationAav_(n)(Kθ_(n)=+Sin⁻¹(Aav_(n))).

In step S75, it is determined whether the second digital accelerationAav_(n) is less than 0. When it is determined that the second digitalacceleration Aav_(n) is less than 0, the operation proceeds to step S77,otherwise, the operation continues to step S76.

In step S76, the CPU 21 determines that the photographic apparatus 1 isheld approximately in the first horizontal orientation, and calculatesthe inclination angle (the third digital displacement angle Kθ_(n)) byperforming the arcsine transformation on the first digital accelerationAah_(n)(Kθ_(n)=+Sin⁻¹(Aah_(n))).

In step S77, the CPU 21 determines that the photographic apparatus isheld approximately in the second horizontal orientation, and calculatesthe inclination angle (the third digital displacement angle Kθ_(n)) byperforming the arcsine transformation on the first digital accelerationAah_(n) and taking the negative (Kθ_(n)=−Sin⁻¹(Aah_(n))).

Furthermore, it is explained that the hall sensor is used for positiondetection as the magnetic-field change-detecting element. However,another detection element, an MI (Magnetic Impedance) sensor such as ahigh-frequency carrier-type magnetic-field sensor, a magneticresonance-type magnetic-field detecting element, or an MR(Magneto-Resistance effect) element may be used for position detectionpurposes. When one of either the MI sensor, the magnetic resonance-typemagnetic-field detecting element, or the MR element is used, theinformation regarding the position of the movable platform can beobtained by detecting the magnetic-field change, similar to using thehall sensor.

Furthermore, the CPU 21 determines which of the translational movement(the first and second stabilizations) or the inclination correction asthe rotational movement is to be performed, corresponding to the valueof the holding state parameter HND immediately before the shutterrelease switch 13 a is set to the ON state.

However, instead of the inclination correction, a third stabilizationfor correcting the hand shake caused by roll (the third hand-shakedisplacement angle around the z direction) may be performed as therotational movement.

Namely, the CPU 21 may determine which of the translational movement orthe rotational movement is to be performed as the movement control ofthe movable platform 30 a, corresponding to the value of the holdingstate parameter HND.

In this case, the hand-shake angle (the third hand-shake quantity)caused by roll that corresponds to the third digital displacement angleKθ_(n) can be calculated by the acceleration sensor 26 c. However, itcould be calculated by another sensor such as an angular velocitysensor, etc.

Although the embodiment of the present invention has been describedherein with reference to the accompanying drawings, obviously manymodifications and changes may be made by those skilled in this artwithout departing from the scope of the invention.

The present disclosure relates to subject matter contained in JapanesePatent Application No. 2008-092465 (filed on Mar. 31, 2008), which isexpressly incorporated herein by reference, in its entirety.

1. A photographic apparatus comprising: a movable platform which has animager that captures an optical image through a taking lens, and ismovable and rotatable in an xy plane perpendicular to an optical axis ofsaid taking lens; and a controller that performs a movement control ofsaid movable platform for one of a translational movement and arotational movement, said translational movement including at least oneof a first stabilization for correcting hand shake caused by yaw aroundthe y direction and a second stabilization for correcting hand shakecaused by pitch around the x direction, said x direction beingperpendicular to said optical axis, said y direction being perpendicularto said x direction and said optical axis, said rotational movementrotating said movable platform in said xy plane; said controllerdetermining which of said translational movement and said rotationalmovement is to be performed, on the basis of a first hand-shakeparameter caused by yaw that is calculated for said first stabilizationand a second hand-shake parameter caused by pitch that is calculated forsaid second stabilization.
 2. The photographic apparatus according toclaim 1, wherein said first hand-shake parameter is a first angularvelocity caused by yaw; said second hand-shake parameter is a secondangular velocity caused by pitch; and said controller determines thatsaid translational movement is to be performed, when at least one of theabsolute value of said first angular velocity and the absolute value ofsaid second angular velocity is greater than a threshold.
 3. Thephotographic apparatus according to claim 1, wherein said rotationalmovement is an inclination correction based on an inclination angle ofsaid photographic apparatus formed by rotation of said photographicapparatus around said optical axis, as measured with respect to a levelplane perpendicular to the direction of gravitational force.
 4. Thephotographic apparatus according to claim 3, further comprising anacceleration sensor that detects a first gravitational component and asecond gravitational component, said first gravitational component beingthe component of gravitational acceleration in said x direction, andsaid second gravitational component being the component of gravitationalacceleration in said y direction; wherein said controller calculatessaid inclination angle, on the basis of a magnitude relation between theabsolute value of said first gravitational component and the absolutevalue of said second gravitational component, and performs a movementcontrol of said movable platform for said inclination correction basedon said inclination angle.
 5. The photographic apparatus according toclaim 4, wherein said controller calculates said inclination angle byperforming an arcsine transformation on the smaller of the absolutevalue of said first gravitational component and the absolute value ofsaid second gravitational component.
 6. The photographic apparatusaccording to claim 4, wherein said x direction is perpendicular to thedirection of gravitational force and said y direction is parallel to thedirection of gravitational force when said photographic apparatus isheld horizontally and either an upper surface or a lower surface of saidphotographic apparatus faces upward; and said x direction is parallel tothe direction of gravitational force and said y direction isperpendicular to the direction of gravitational force when saidphotographic apparatus is held vertically and one of either sidesurfaces of said photographic apparatus faces upward.
 7. Thephotographic apparatus according to claim 1, wherein said rotationalmovement is a third stabilization for correcting hand shake caused byroll around the z direction parallel to said optical axis.
 8. Thephotographic apparatus according to claim 1, wherein said controllerdetermines that said translational movement is to be performed, when atleast one of said first and second hand-shake parameters is greater thana threshold; and said controller determines that said rotationalmovement is to be performed, when said first and second hand-shakeparameters are not greater than said threshold.
 9. The photographicapparatus according to claim 1, wherein, when at least one of theabsolute value of the first handshake parameter is greater than a firstthreshold value and the absolute value of the second handshake parameteris greater than a second threshold value, said controller performsmovement control of said movable platform for translational movement.10. The photographic apparatus according to claim 9, wherein, when theabsolute value of the first handshake parameter is not greater than thefirst threshold value and the absolute value of the second handshakeparameter is not greater than the second threshold value, saidcontroller does not perform movement control of said movable platformfor translational movement and performs movement control of said movableplatform for rotational movement.
 11. The photographic apparatusaccording to claim 1, said controller being configured so that whenmovement control of said movable platform for rotational movement isperformed, movement control of said movable platform for translationalmovement is precluded, and when movement control of said movableplatform for translational movement is performed, movement control ofsaid movable platform for rotational movement is precluded.
 12. Aphotographic apparatus comprising: a movable platform which has animager that captures an optical image through a taking lens, and ismovable and rotatable in an xy plane perpendicular to an optical axis ofsaid taking lens; a first sensor that detects a first angular velocitycaused by yaw around the y direction, said y direction beingperpendicular to said optical axis; a second sensor that detects asecond angular velocity caused by pitch around the x direction, said xdirection being perpendicular to said optical axis and said y direction;and a controller that performs a movement control of said movableplatform for a rotational movement, said rotational movement rotatingsaid movable platform in said xy plane; said controller determining thatsaid rotational movement is to be performed, when the absolute value ofsaid first angular velocity and the absolute value of said secondangular velocity are not greater than a threshold.